Sheet carrying path switching mechanism and sheet folding device

ABSTRACT

A folding device includes a first folded-sheet clamping device and a second folded-sheet clamping device that are arranged on a decelerating roller. A first cam causes the first clamping device and the second clamping device to release a folded sheet into any one of a first sheet discharge path and a second sheet discharge path. When two folded sheets are held by each of the clamping devices, a second cam controls part of the first cam to cause the second clamping device not to release a sheet into the first sheet discharge path and to release a sheet into the second sheet discharge path.

RELATED APPLICATIONS

The present application is based on, and claims priority from, Japan Application Number 2006-30411, filed Nov. 9, 2006, the disclosure of which is hereby incorporated by reference herein in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a technology for folding sheets.

2. Description of the Related Art

In a printing machine, such as a rotary printing machine, an image is printed on a paper web and the paper web is cut into sheets of predetermined size. A folding device then folds the sheets at a predetermined position. A sheet carrying device having a plurality of paths for carrying the sheets and a path switching device that switches between the paths is used for that purpose in the printing machines. For example, Japanese Patent Application Laid-Open No. 2002-60128 [Paragraph: 0012, FIG. 1] discloses a conventional carrying path switching device.

In the conventional carrying path switching device, a folding roller folds a sheet, and the folded sheet is delivered to a holding roller. The holding roller includes holding units, and receives the folded sheet from the folding roller. Upon receiving the folded sheet, the holding roller holds the sheet by the holding unit to deliver the sheet to a first carrying roller (decelerating roller) or a second carrying roller (decelerating roller). When a plurality of folded sheets are carried by each of the holding units, a switching unit controls some of the holding units to hold the sheet, and some other of the holding units not to hold the sheet at a receiving position to receive the sheet from the folding unit. In the carrying path switching device, each of the first and the second carrying rollers is a decelerating roller, serving as the last roller where the sheet is delivered to before the sheet reaches a carrying path.

The folded sheet can be delivered to the first carrying roller or the second carrying roller, and then discharged to a first carrying path or a second carrying path. The folded sheet can be alternately discharged to the first carrying path and the second carrying path. However, when a plurality of folded sheets is carried by each of the holding unit, the folded sheets are delivered exclusively to the first carrying path.

Because the two decelerating rollers rotate at a lower circumferential velocity than the holding roller, the folded sheet is often delivered in an unsteady manner to the decelerating roller from the holding roller. To assuredly deliver the folded sheet to the decelerating roller from the holding roller, such a sheet delivery needs to be performed with high accuracy, and the decelerating roller needs to be arranged with respect to the holding roller with high precision. In other words, it is necessary to provide the same number of decelerating rollers as the carrying path. Therefore, the decelerating roller and the holding roller need to be arranged with high precision, making their configuration complicated. Furthermore, because the decelerating roller is expensive, costs of the folding device increase as the number of decelerating rollers increases.

SUMMARY OF THE INVENTION

It is an object of the present invention to at least partially solve the problems in the conventional technology.

According to an aspect of the present invention, there is provided a folded-sheet carrying path switching mechanism that carries a pile of folded sheets, the folded sheets being in a predetermined shape and size. The folded-sheet carrying path switching mechanism includes a delivering unit that receives the pile and delivers the pile to one of a first path and a second path, the delivering unit including a rotatable member; a first holding unit that is mounted on the rotatable member, and configured to receive the pile in a first position while the rotatable member is rotating and deliver the pile to the first path; and a second holding unit that is mounted on the rotatable member, and configured to receive the pile in a second position while the rotatable member is rotating and deliver the pile to one of the first path and the second path; and a switching unit that includes a releasing unit that causes the first holding unit to release the pile into the first path and causes the second holding unit to release the pile into any one of the first path and the second path; and a control unit that controls the releasing unit to cause the second holding unit to release the pile in any one of the first path and the second path depending on number of folded sheets in the pile.

According to another aspect of the present invention, there is provided a folding device including a folding roller that configured to fold a sheet in a predetermined shape and size, and produce a pile of folded sheets; and a folded-sheet carrying path switching mechanism. The folded-sheet carrying path switching mechanism includes a delivering unit that receives the pile and delivers the pile to one of a first path and a second path, the delivering unit including a rotatable member; a first holding unit that is mounted on the rotatable member, and configured to receive the pile in a first position while the rotatable member is rotating and deliver the pile to the first path; and a second holding unit that is mounted on the rotatable member, and configured to receive the pile in a second position while the rotatable member is rotating and deliver the pile to one of the first path and the second path; and a switching unit that includes a releasing unit that causes the first holding unit to release the pile into the first path and causes the second holding unit to release the pile into any one of the first path and the second path; and a control unit that controls the releasing unit to cause the second holding unit to release the pile in any one of the first path and the second path depending on number of folded sheets in the pile.

The above and other objects, features, advantages and technical and industrial significance of this invention will be better understood by reading the following detailed description of presently preferred embodiments of the invention, when considered in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a folding device according to an embodiment of the present invention;

FIG. 2A is a schematic diagram of a pile of one folded sheet and FIG. 2B is a schematic diagram of a pile of two folded sheets;

FIG. 3 is a side view of a decelerating roller shown in FIG. 1;

FIGS. 4 to 6 are views of the decelerating roller;

FIGS. 7A to 7C are schematic diagrams for explaining operation performed by a sheet-delivery switching mechanism shown in FIG. 6;

FIGS. 8 and 9 are schematic diagrams for explaining operation performed by a folded-sheet delivery guide shown in FIG. 1;

FIG. 10 is a schematic diagram of a cam follower shown in FIG. 8; and

FIG. 11 is a diagram of a modification example of the folded-sheet delivery guide shown in FIG. 8.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Exemplary embodiments of the present invention are described in detail below with reference to the accompanying drawings.

According to an embodiment of the present invention, a folding device includes a first sheet holding unit and a second sheet holding unit. The first and the second sheet holding units are arranged on a decelerating roller that is a sheet delivering unit. The folding device further includes a first sheet releasing unit and a second sheet releasing unit. The first sheet releasing unit causes the first sheet holding unit and the second sheet holding unit to release a folded sheet into a first sheet discharge path. The second sheet releasing unit causes at least the second sheet holding unit from among the first sheet holding unit and the second sheet holding unit to release a folded sheet into a second sheet discharge path. The folding device controls the first sheet releasing unit to cause the second sheet holding unit not to release the folded sheet depending on the number of folded sheets in a pile, i.e., the number of sheets held by each of the sheet holding units.

FIG. 1 is a schematic diagram of a folding device 1 according to the embodiment. FIG. 2A is a schematic diagram of a pile containing one folded sheet and FIG. 2B is a schematic diagram of a pile containing two folded sheets laid one on top of another. Thus, a pile can contain one or more folded sheets. The folding device 1 is configured to cut out a paper web W, on which a predetermined image has been printed by a printing machine 40, thereby producing sheets of predetermined size, and then fold those sheets at a predetermined position.

The paper web W is first delivered between a folding roller 2 and a cutting roller 3. A guide pin 2N arranged on the outer circumference of the folding roller 2 holds the paper web W. The cutting roller 3 cuts the paper web W, which is held by the guide pin 2N, into a sheet S1 of a predetermined size. The sheet S1 is then passed between the folding roller 2 and a holding roller 4. The sheet S1 is folded at a predetermined position when it passes between the folding roller 2 and the holding roller 4. The folded sheet is referred to below as a folded sheet S. The folded sheet S is held by a holding claw 4N attached on the holding roller 4, and conveyed to a decelerating roller 5 that is a sheet delivering unit.

The guide pin 2N on the folding roller 2 can hold one or more sheets at a time. When one sheet is held by the guide pin 2N, the sheet is folded between the folding roller 2 and the holding roller 4, resulting in a pile of one folded sheet S shown in FIG. 2A. When a plurality of sheets (say two sheets) are held by the guide pin 2N, all those sheets are folded resulting in a pile of plurality of folded sheets shown in FIG. 2B. To produce a plurality of the folded sheets S (e.g., two sheets) in piles, the cutting roller 3 cuts out the paper web W in a predetermined size to produce the first sheet S1, and then the first sheet S1 passes between the folding roller 2 and the holding roller 4 without being folded by the folding roller 2. A new portion of the paper web W is then laid over the first sheet S1 on the folding roller 2, and the cutting roller 3 cuts out the paper web W thereby producing the second sheet S1 of a predetermined size. As a result, the second sheet S1 is laid on top of the first sheet S1. The first and the second sheets S1 are folded together between the folding roller 2 and the holding roller 4 to produce the pile of two folded sheets S as shown in FIG. 2B. The cutting the paper web into sheets, making a pile of the sheets, and folding the pile of sheets is repeated for a required number of times.

The (pile of) folded sheet S is then delivered to the decelerating roller 5. The decelerating roller 5 is rotated at a lower circumferential velocity than that of the holding roller 4. The decelerating roller 5 includes a plurality of holding claws 5N, as sheet holding units, on its circumference. One of those holding claws 5N receives the folded sheet S from the holding roller 4.

The decelerating roller 5 delivers the folded sheet S to a first sheet discharge path 7J or a second sheet discharge path 7K. How the decelerating roller 5 delivers the folded sheet S to the first sheet discharge path 7J is explained below. When the decelerating roller 5 is to deliver the folded sheet S to the first sheet discharge path 7J, a folded-sheet delivery guide 11 moves in the direction indicated by an arrow G2 shown in FIG. 1 (the delivery guide 11 moves towards the decelerating roller 5). Because the decelerating roller 5 is rotating and because the delivery guide 11 has moved to the decelerating roller 5, the folded sheet S is delivered to a first carrier 12J included in the first sheet discharge path 7J. When the holding claws 5N releases the folded sheet S upon reaching the first carrier 12J, the folded sheet S is delivered to the first carrier 12J.

How the decelerating roller 5 delivers the folded sheet S to the second sheet discharge path 7K is explained below. When the decelerating roller 5 is to deliver the folded sheet S to the second sheet discharge path 7K, the delivery guide 11 moves in the direction indicated by an arrow G1 shown in FIG. 1 (the delivery guide 11 moves away from the decelerating roller 5). Because the decelerating roller 5 is rotating and because the delivery guide 11 has moved away from the decelerating roller 5, the folded sheet S passes between the delivery guide 11 and the decelerating roller 5, and it is delivered toward a guide roller 6. The folded sheet S is held by a holding claw 6N arranged on the guide roller 6, and then delivered from the decelerating roller 5 to the guide roller 6. The holding claw 6N releases the folded sheet S upon reaching a second carrier 12K included in the second sheet discharge path 7K. The folded sheet S is then delivered to the second carrier 12K. In this manner, the folded sheet S can be delivered to a desired one of the first sheet discharge path 7J and the second sheet discharge path 7K.

In the first sheet discharge path 7J, the first carrier 12J conveys the folded sheet S to a first impeller 9J, and the folded sheet S is temporarily stored in the first impeller 9J. The folded sheet S is then conveyed to a first stacker 10J, which is a storage device corresponding to the first impeller 9J, and stored in the first stacker 10J.

On the other hand, in the second sheet discharge path 7K, the second carrier 12K conveys the folded sheet S to a second impeller 9K, and the folded sheet S is temporarily stored in the second impeller 9K. The folded sheet S is then conveyed to a second stacker 10K, which is a storage device corresponding to the second impeller 9K, and stored in the second stacker 10K.

The first sheet discharge path 7J and the second sheet discharge path 7K includes a first chopper folding device 8J and a second chopper folding device 8K, respectively, to fold the folded sheet S tightly. The first chopper folding device 8J and the second chopper folding device 8K can be omitted if there is no need to fold the folded sheet S tightly.

FIG. 3 is an enlarged side view of the decelerating roller 5, FIG. 4 is a front view of the decelerating roller 5, and FIG. 5 is an enlarged side view of a portion of the decelerating roller 5. As shown in FIG. 3, the decelerating roller 5 includes four folded-sheet holding units, first to fourth folded-sheet clamping devices 20A, 20B, 20C, and 20D, on its outer circumference. The four clamping devices 20A, 20B, 20C, 20D are separated from one another by 90 degrees with respect to a rotation axis Z of the decelerating roller 5.

The four clamping devices 20A, 20B, 20C, and 20D are collectively referred to as a clamping device in the following description. Only the first and the second clamping devices 20A, 20B are shown in FIG. 4; moreover, the decelerating roller 5 is assumed to be transparent. In other words, if the decelerating roller 5 is not transparent, because the first and the second clamping devices 20A, 20B are on opposite sides of the axis Z, they can not be seen in the manner shown in FIG. 4. All the first to the fourth clamping devices 20A, 20B, 20C, 20D have the same or similar configuration, therefore the first and the second clamping devices 20A and 20B are only explained in detail below.

The first clamping device 20A has a plurality of the holding claws 5N attached on a shaft 21, and the holding claws 5N are arranged in the axial direction of the shaft 21. A crank 22 is attached on one end of the shaft 21, and when the crank 22 swings around the shaft 21, the holding claws 5N move toward or away from the decelerating roller 5. When the holding claws 5N move toward the decelerating roller 5, the folded sheet S is sandwiched between the holding claws 5N and the decelerating roller 5. In contrast, when the holding claws 5N move away from the decelerating roller 5, the folded sheet S is released from the holding claws 5N.

A cam follower (a first cam follower 23X as an example) is attached on one end of the crank 22 while the other end of the crank 22 is connected to the shaft 21, and the first cam follower 23X is moved by a cam (a first cam 24X as an example). The rotation of the decelerating roller 5 causes the first to the fourth clamping devices 20A to 20D mounted on the decelerating roller 5 to rotate. While the decelerating roller 5 rotates, the first cam follower 23X moves while in contact with the outer circumference of the first cam 24X. Accordingly, the first cam follower 23X moves along a form of the outer circumference of the first cam 24X.

As shown in FIG. 5, a cam moving portion 24XR, which is a concave portion like a recess, is formed on the outer circumference of the first cam 24X. Because the first cam 24X is substantially circular, the first cam follower 23X does not swing around the shaft 21 along the outer circumference of the first cam 24X, although the first cam follower 23X swings while moving along the cam moving portion 24XR. When the first cam follower 23X does not swing around the shaft 21, i.e., the holding claws 5N have moved toward the decelerating roller 5, the folded sheet S is sandwiched between the holding claws 5N and the decelerating roller 5. When the first cam follower 23X moves along the cam moving portion 24XR, the first cam follower 23X moves toward the center of the first cam 24X. Accordingly, the crank 22 moves toward the center of the first cam 24X and swings around the shaft 21, i.e., the crank 22 moves toward the axis Z of the decelerating roller 5. As a result, the holding claws 5N move away from the decelerating roller 5 so that the folded sheet S is released from the holding claws 5N.

The second clamping device 20B functions in substantially the same manner as the first clamping device 20A. However, there is a difference in that the second clamping device 20B is configured to discharge the folded sheet S to the first sheet discharge path 7J or the second sheet discharge path 7K depending on the number of folded sheets S in the pile. The second clamping device 20B includes a cam (a second cam 24Y) to switch the paths between the first sheet discharge path 7J and the second sheet discharge path 7K, and a second cam follower 23Y in contact with the second cam 24Y. The second cam follower 23Y is concentrically arranged with respect to the first cam follower 23X.

As shown in FIG. 3, the first clamping device 20A and the second clamping device 20B are arranged in opposite positions, i.e., they are spaced from each other by an angle of 180 degrees with respect to the axis Z. Similarly, the third clamping device 20C and the fourth clamping device 20D are arranged in opposite positions, i.e., they are spaced from each other by an angle of 180 degrees with respect to the axis Z.

The first clamping device 20A is configured to discharge the folded sheet S only to the first sheet discharge path 7J, the second clamping device 20B is configured to discharge the folded sheet S to one of the first sheet discharge path 7J and the second sheet discharge path 7K depending on the number of folded sheets in the pile, and the third and the fourth clamping devices 20C and 20D are configured to discharge the folded sheet S only to the second sheet discharge path 7K. The second clamping device 20B discharges the folded sheet S to one of the first sheet discharge path 7J and the second sheet discharge path 7K depending on the number of folded sheets S in the pile.

Concretely, when the pile contains one folded sheet S, the second clamping device 20B discharges the pile to the first sheet discharge path 7J. On the other hand, when the pile contains two folded sheets S, the second clamping device 20B discharges the pile to the second sheet discharge path 7K.

FIG. 6 is a view of the decelerating roller from a different direction. FIGS. 7A to 7C are schematic diagrams for explaining operation performed by a sheet-delivery switching mechanism 24 included in the folding device 1. The sheet-delivery switching mechanism 24 (sheet-delivery switching unit) includes the first cam 24X and the second cam 24Y. The first cam 24X and the second cam 24Y are arranged on one side of the decelerating roller 5 in the manner that the first and the second cams 24X, 24Y move together with the decelerating roller 5. The second cam 24Y is rotated by an actuator 28 that is a unit for driving the sheet-delivery switching mechanism 24 around the axis Z. The use of the actuator 28 makes it possible to control the sheet-delivery switching mechanism 24 remotely or automatically.

As shown in FIG. 6, each of the first cam followers 23X of the first clamping device 20A and the second clamping device 20B are in contact with the outer circumference of the first cam 24X. As shown in FIG. 7A, the first cam 24X includes a plurality of concave portions (three concave portions are shown in the diagrams) on and along the circumference of the first cam 24X. The three concave portions are: a first moving portion 24XA, a second moving portion 24XB, and a third moving portion 24XC. The moving portions 24XA, 24XB, 24XC move each of the first cam followers 23X of the first clamping device 20A and the second clamping device 20B. The first cam 24X is substantially circular, and a circular portion of the first cam 24X, excluding the moving portions 24XA, 24XB, 24XC, has a radius r1.

The first moving portion 24XA is configured to cause the clamping device (the first and the second clamping devices 20A, 20B) to receive the folded sheet S from the holding roller 4 (see FIG. 1). When the first cam follower 23X moves along the first moving portion 24XA, the holding claws 5N of the clamping device move away from the decelerating roller 5 in the manner described in connection with FIG. 5. The holding claws 5N then hold the folded sheet S between the deceleration roller 5.

The second moving portion 24XB (a first sheet releasing unit) and the third moving portion 24XC (a second sheet releasing unit) are configured to cause the clamping device to release the folded sheet S held between the holding claws 5N and the deceleration roller 5. The second moving portion 24XB is configured to cause the first and the second clamping devices 20A, 20B to release the folded sheet S and discharge the released folded sheet S to the first sheet discharge path 7J. When the first cam follower 23X moves along the second moving portion 24XB, the holding claws 5N of each of the first and the second clamping device 20A, 20B move away from the decelerating roller 5. Accordingly, the folded sheet S is released, and the released folded sheet S is discharged to the first sheet discharge path 7J.

The third moving portion 24XC is configured to cause the second clamping device 20B to release the folded sheet S and discharge the released folded sheet S to the second sheet discharge path 7K. When the first cam follower 23X of the second clamping device 20B moves along the third moving portion 24XC, the holding claws 5N of the second clamping device 20B move away from the decelerating roller 5. Accordingly, the folded sheet S is released, and the released folded sheet S is discharged to the second sheet discharge path 7K.

As shown in FIG. 6, the outer circumference of the second cam 24Y is in contact with the second cam follower 23Y of the second clamping device 20B. As shown in FIG. 7A, the second cam 24Y has a substantially fan shape, and a circular portion of the second cam 24Y has a radius r2. The radius r2 of the second cam 24Y is equal to the radius r1 of the first cam 24X. When the second cam follower 23Y moves along the outer circumference of the second cam 24Y, the second cam follower 23Y does not swing around the shaft 21. As a result, the holding claws 5N of the second clamping device 20B does not move away from the decelerating roller 5, and the holding claws 5N of the second clamping device 20B keep holding the folded sheet S. Thus, the second cam 24Y causes the second clamping device 20B to keep holding the folded sheet S while passing the first sheet discharge path 7J.

When the pile contains one folded sheet S, i.e., when one folded sheet S is held by the second clamping device 20B, the second clamping device 20B discharges the folded sheet S to the first sheet discharge path 7J. To discharge the pile that contains one folded sheet S to the first sheet discharge path 7J, the second clamping device 20B is moved by the first cam 24X. More specifically, the actuator 28 moves the second cam 24Y to be positioned on the circular portion of the first cam 24X, so that the first cam 24X causes the moving portions 24XA, 24XB, and 24XC to move the second clamping device 20B.

Because the first clamping device 20A discharges the folded sheet S only to the first sheet discharge path 7J, the first clamping device 20A is moved by the movement of the first cam follower 23X along the first cam 24X. As a result, the first cam 24X causes the moving portions 24XA, 24XB, and 24XC to move the first clamping device 20A. More specifically, when one folded sheet S is held by each of the first and the second clamping devices 20A, 20B, each of the first and the second clamping devices 20A, 20B is moved by the first moving portion 24XA to hold the folded sheet S, and is moved by the second moving portion 24XB to release the folded sheet S, thereby discharging the folded sheet S to the first sheet discharge path 7J. Although each of the first and the second clamping devices 20A, 20B is moved by the third moving portion 24XC to cause the holding claws 5N to move away from the decelerating roller 5, the first and the second clamping devices 20A, 20B do not perform any operation because the first and the second clamping devices 20A, 20B have discharged the folded sheet S to the first sheet discharge path 7J.

When the pile contains two folded sheets S, i.e., two folded sheets S are held by each of the first and the second clamping devices 20A and 20B, the first clamping device 20A discharges the folded sheets S to the first sheet discharge path 7J while the second clamping device 20B discharges the folded sheets S to the second sheet discharge path 7K. As described above, after receiving the folded sheets S from the holding roller 4, the decelerating roller 5 reaches the first sheet discharge path 7J before reaching the second sheet discharge path 7K. When the second clamping device 20B is moved by the first cam 24X, the first cam 24X causes the moving portions 24XA, 24XB, and 24XC to move the second clamping device 20B. As a result, the second clamping device 20B is moved by the second moving portion 24XB to release the folded sheet S into the first sheet discharge path 7J before the second clamping device 20B is moved by the third moving portion 24XC to release the folded sheet S into the second sheet discharge path 7K. Thus, the second clamping device 20B can not discharge the folded sheet S to the second sheet discharge path 7K.

To prevent the second clamping device 20B from releasing the folded sheet S into the first sheet discharge path 7J, the actuator 28 moves the second cam 24Y toward the second moving portion 24XB (in the direction indicated by an arrow E shown in FIG. 7B), so that the second cam 24Y is positioned over the second moving portion 24XB. It is not necessary to use the actuator 28 for moving the second cam 24Y. For example, the second cam 24Y can be permanently attached over the first moving portion 24XA when necessary, i.e., when a plurality of folded sheets is discharged to the sheet discharge paths. Thus, it is possible to save costs and spaces for providing the actuator 28.

As described above, the first cam 24X causes the first moving portion 24XA and the third moving portion 24XC to move the second clamping device 20B, and the second cam 24Y causes the second moving portion 24XB not to move the second clamping device 20B. More specifically, the second cam 24Y is positioned over the second moving portion 24XB, and the second cam follower 23Y is in contact with the second cam 24Y (the second cam follower 23Y is arranged concentrically with respect to the first cam follower 23X), so that the second cam 24Y prevents the second cam follower 23Y of the second clamping device 20B from moving toward the center of the first cam 24X. Thus, when the first cam follower 23X moves along the second moving portion 24XB, the holding claws 5N of the second clamping device 20B does not move away from the decelerating roller 5. When two folded sheets S are held by the second clamping device 20B, the second clamping device 20B keeps holding the folded sheet S while passing the first sheet discharge path 7J.

When the second clamping device 20B holding the two folded sheets S reaches the second sheet discharge path 7K by the rotation of the decelerating roller 5, the first cam 24X causes the third moving portion 24XC to move the second clamping device 20B; because, the second cam 24Y is not positioned over the third moving portion 24XC. The first and the second cam followers 23X, 23Y of the second clamping device 20B then move toward the center of the first cam 24X and swing around the shaft 21. Accordingly, the holding claws 5N of the second clamping device 20B move away from the decelerating roller 5 to release the folded sheets S, and the folded sheet S is discharged to the second sheet discharge path 7K.

Although theoretically the first clamping device 20A and the second clamping device 20B usually receive the folded sheet S from the holding roller 4 at the one position, in practice the positions at which each of the first and the second clamping devices 20A and 20B receive the folded sheet S from the holding roller 4 can be different.

As described above, the second cam 24Y causes part of the first cam 24X not to move the second clamping device 20B, so that the second clamping device 20B discharges the folded sheet S to the first sheet discharge path 7J or second sheet discharge path 7K depending on the number of folded sheets S held by each of the clamping devices. As a result, when a plurality of the folded sheets S (two sheets according to the embodiment) are held by each of the first and the second clamping devices 20A and 20B, the first clamping device 20A discharges the folded sheets S to the first sheet discharge path 7J, while the second clamping devices 20B discharges the folded sheets S to the second sheet discharge path 7K. Therefore, it is possible to use the carriers 12J, 12K (see FIG. 1) in the first and the second sheet discharge paths 7J, 7K at the same frequency. Thus, the carriers 12J, 12K will be worn down in similar extent.

Because the two sheet discharge paths 7J, 7K are used according to the embodiment, the two storage devices (the first and the second stackers 10J, 10K shown in FIG. 1) arranged in the first and the second sheet discharge paths 7J, 7K, respectively can be used. As a result, it is possible to reduce the frequency of collecting the folded sheets S from the storage device. Furthermore, compared to the case where one sheet discharge path is used, because the two sheet discharge paths 7J, 7K are used according to the embodiment, each of the folded sheets S can be delivered at longer intervals to the chopper folding device (the first and the second chopper folding devices 8J, 8K shown in FIG. 1). As a result, the chopper folding device can fold the folded sheet S with longer folding time. Furthermore, because each of the folded sheets S can be delivered at longer intervals to the impeller (the first and the second impellers 9J, 9K shown in FIG. 1), the impeller can receive the folded sheet S with longer receiving time. As described above, the two sheet discharge paths 7J, 7K are used according to the embodiment, it is possible to take more time for a process performed after the folded sheet S is delivered to the sheet discharge path. Therefore, the devices to be used in a subsequent process can be operated with less load, and reduction of durability of the devices can be suppressed.

Each of the third and the fourth clamping devices 20C, 20D (see FIG. 3) discharges the folded sheet S only to the second sheet discharge path 7K. A third cam 25X shown in FIG. 7C is used to move the third and the fourth clamping devices 20C, 20D.

As shown in FIG. 7C, the third cam 25X has a plurality of concave portions (two concave portions according to the embodiment) on its outer circumference. One of the two concave portions is referred to as a first moving portion 25XA, and the other as a second moving portion 25XB. The first and the second moving portions 25XA, 25XB move each of the third and the fourth clamping devices 20C, 20D. The first moving portion 25XA is configured to cause the third and the fourth clamping devices 20C, 20D to receive the folded sheet S from the holding roller 4 (see FIG. 1). When a cam follower (not shown) of each of the third and the fourth clamping devices 20C, 20D moves along the first moving portion 25XA, the holding claws 5N of each of the third and the fourth clamping devices move away from the decelerating roller 5 in the manner described in connection with FIG. 5. Accordingly, the holding claws 5N of the third and the fourth clamping devices 20C, 20D hold the folded sheet S, and each of the third and the fourth clamping devices receives the folded sheet S from the holding roller 4.

The second moving portion 25XB is configured to cause the third and the fourth clamping devices 20C, 20D to release the folded sheet S from the holding claws 5N, thereby discharging the folded sheet S to the second sheet discharge path 7K. When a cam follower (not shown) of each of the third and the fourth clamping devices 20C, 20D moves along the second moving portion 25XB, the holding claws 5N of each of the third and the fourth clamping devices move away from the decelerating roller 5. Accordingly, the folded sheet S is released from the holding claws 5N and discharged to the second sheet discharge path 7K.

FIGS. 8 to 10 are schematic diagrams for explaining operation performed by the folded-sheet delivery guide 11 included in the folding device 1. The delivery guide 11 is configured to swing around a supporting shaft 11S, and delivers the folded sheet S to a first side EX1 leading to the first sheet discharge path 7J or a second side EX2 leading to the second sheet discharge path 7K. The delivery guide 11 includes an arm 14 to swing the delivery guide 11. The delivery guide 11 is attached to one end of the arm 14, and a cam follower 13 is attached to the other end of the arm 14.

As shown in FIG. 10, the cam follower 13 includes a first cam follower 13X and a second cam follower 13Y, and the cam followers 13X, 13Y are rotatable around the axis Zc. The first cam follower 13X is in contact with a first rotating cam 30, and the second cam follower 13Y is in contact with a second rotating cam 31. The first and the second rotating cams 30, 31 are rotatable around one axis Zc, and each of the first and the second rotating cams 30, 31 rotates in synchronization with (at the same rotating speed as) the decelerating roller 5.

When the folded sheet S is to be discharged to the first sheet discharge path 7J, the delivery guide 11 moves in the direction indicated by an arrow G2 shown in FIG. 1 (in the direction such that the delivery guide 11 moves toward the decelerating roller 5). As a result, the folded sheet S passes through a side of the delivery guide 11 to which the decelerating roller 5 is not opposed and is delivered through the first side EX1. On the other hand, when the folded sheet S is to be discharged to the second sheet discharge path 7K, the delivery guide 11 moves in the direction indicated by an arrow G1 shown in FIG. 1 (in the direction such that the delivery guide 11 moves away from the decelerating roller 5). As a result, the folded sheet S passes between the delivery guide 11 and the decelerating roller 5, and is delivered through the second side EX2.

There are two discharge modes (the first and the second discharge modes) according to the embodiment. In the first discharge mode, the folded sheet S is released from the first clamping device 20A (a first sheet holding unit) and the second clamping device 20B (a second sheet holding unit), and is then discharged to the first sheet discharge path 7J. In the first discharge mode, one folded sheet S is held by each of the clamping devices. On the other hand, in the second discharge mode, the folded sheet S released from the first clamping device 20A is discharged to the first sheet discharge path 7J, and the folded sheet S released from the second clamping device 20B is discharged to the second sheet discharge path 7K. In the second discharge mode, a plurality of the folded sheets S (two sheets according to the embodiment) is held by each of the clamping devices. The delivery guide 11 is used to switch between the first discharge mode and the second discharge mode.

The delivery guide 11 is moved by the first rotating cam 30 and the second rotating cam 31 through the cam follower 13 and the arm 14. The first rotating cam 30 includes a plurality of concave portions on the outer circumferential portion, and the plurality of concave portions is arranged in the circumferential direction. The concave portions are referred to as a first moving portion 30A and a third moving portion 30C. The first moving portion 30A and the third moving portion 30C are arranged in opposite positions, i.e., spaced from each other by 180 degrees around a central axis Zc of the first rotating cam 30.

A second moving portion 30B and a fourth moving portion 30D are arranged between the first moving portion 30A and the third moving portion 30C. The second moving portion 30B and the fourth moving portion 30D are convex portions with respect to the first and third moving portions 30A, 30C. In the same manner as the first and third moving portions 30A, 30C, the second and the fourth moving portions 30B, 30D are arranged in opposite positions, i.e., spaced from each other by 180 degrees around the central axis Zc of the first rotating cam 30.

When the cam follower 13 moves along the first moving portion 30A and the third moving portion 30C, the cam follower 13 moves toward the central axis Zc of the first rotating cam 30 (in the direction indicated by an arrow F2 in FIG. 8). The delivery guide 11 then moves toward the decelerating roller 5 (in the direction indicated by the arrow G2 in FIG. 8), so that the folded sheet S is delivered through the first side EX1.

When the cam follower 13 moves along the second moving portion 30B and the fourth moving portion 30D, the cam follower 13 moves away from the central axis Zc (in the direction indicated by an arrow F1 shown in FIG. 8). The delivery guide 11 then moves away from the decelerating roller 5 (in the direction indicated by the arrow G1 in FIG. 8), so that the folded sheet S is delivered through the second side EX2.

When one folded sheet S is held by each of the clamping devices, each of the first and the second clamping devices 20A, 20B discharges the folded sheet S to the first sheet discharge path 7J (the first discharge mode). To discharge the folded sheet S to the first sheet discharge path 7J, the delivery guide 11 moves toward the decelerating roller 5 when each of the first and the second clamping devices 20A, 20B releases the folded sheet S. Because each of the third and the fourth clamping devices 20C, 20D discharges the folded sheet S to the second sheet discharge path 7K, the delivery guide 11 moves away from the decelerating roller 5 when each of the third and the fourth clamping devices 20C, 20D releases the folded sheet S.

As shown in FIG. 3, the first clamping device 20A and the second clamping device 20B are spaced from each other by the central angle of 180 degrees. Therefore, the delivery guide 11 moves toward the decelerating roller 5 each time the decelerating roller 5 rotates 180 degrees. As described above, the first rotating cam 30 rotates in synchronization with (at the same rotating speed as) the decelerating roller 5. Therefore, the cam follower 13 is caused to move along the first moving portion 30A and the third moving portion 30C at a timing for releasing the folded sheet S from each of the first and the second clamping devices 20A, 20B.

When two folded sheets S are held by each of the clamping devices, the first clamping devices 20A discharges the folded sheets S to the first sheet discharge path 7J, and the second clamping device 20B discharges the folded sheets S to the second sheet discharge path 7K (the second discharge mode). If the delivery guide 11 moves in the same manner as when one folded sheet S is delivered, the delivery guide 11 moves toward the decelerating roller 5 (in the direction indicated by the arrow G2 shown in FIG. 8) to discharge the folded sheets S to the first sheet discharge path 7J. Thus, the second clamping device 20B cannot discharge the folded sheet S to the second sheet discharge path 7K.

According to the embodiment, as shown in FIG. 8, a circular portion of the second rotating cam 31 has a radius r2, and the radius r2 equals to a radius r1 of each of the second and the fourth moving portions 30B, 30D of the first rotating cam 30. The second rotating cam 31 is placed over the third moving portion 30C of the first rotating cam 30, so that the second rotating cam 31 causes the third moving portion 30C not to move the cam follower 13 (see FIG. 9). The second rotating cam 31 can be automatically placed over the third moving portion 30C by using a driving unit such as an actuator. Thus, the first and the second sheet discharge paths 7J, 7K can be automatically switched over by an actuator that drives the second rotating cam 31 in cooperation with the actuator 28 (see FIG. 6) that drives the second cam 24Y in the sheet-delivery switching mechanism 24. The second rotating cam 31 can be attached over the third moving portion 30C when needed, so that it is possible to save costs and spaces for mounting a driving unit that drives the second rotating cam 31.

As shown in FIG. 10, the second rotating cam 31 is in contact with the second cam follower 13Y that is concentrically arranged with the first cam follower 13X. When the cam follower 13 reaches the third moving portion 30C, the second cam follower 13Y prevents the cam follower 13 from moving toward the central axis Zc of the first rotating cam 30.

With the above-described configuration, the delivery guide 11 switches between the first side EX1 and the second side EX2 every time the decelerating roller 5 rotates 360 degrees. When two folded sheets S are held by the second clamping device 20B, the folded sheets S pass between the delivery guide 11 and the decelerating roller 5, and are delivered through the second side EX2. As a result, when two folded sheets S are held by each of the clamping devices, the first clamping device 20A discharges the folded sheets S to the first sheet discharge path 7J, and the second clamping device 20B discharges the folded sheets S to the second sheet discharge path 7K.

FIG. 11 is a diagram of a different configuration example of the delivery guide 11. In this configuration, the delivery guide 11 swings around the supporting shaft 11S by a rotating cam 32. The rotating cam 32 is driven by a motor 35 that is a unit that drives the delivery guide 11. The rotating cam 32 includes a first moving portion 32A and a second moving portion 32B. The first moving portion 32A has a radius r3, the second moving portion 32B has a radius r1, and the radius r3 is smaller than the radius r2. The first moving portion 32A and the second moving portion 32B are arranged in opposite positions, i.e., spaced from each other by 180 degrees around a rotation axis Zc of the rotating cam 32.

When the cam follower 13 moves along the first moving portion 32A, the delivery guide 11 moves toward the decelerating roller 5 (in the direction indicated by an arrow G2 in FIG. 11), so that the folded sheet S is delivered through the first side EX1. When the cam follower 13 moves along the second moving portion 32B, the delivery guide 11 moves away from the decelerating roller 5 (in the direction indicated by an arrow G1 shown in FIG. 11), so that the folded sheet S is delivered through the second side EX2. The rotating cam 32 includes a driven pulley 34 that is concentrically arranged with respect to the central axis Zc of the rotating cam 32. The motor 35 includes a driving pulley 36 that is arranged on a drive axis of the motor 35. A belt 33 is looped around the driven pulley 34 and the driving pulley 36, and the motor 35 rotates the rotating cam 32 through the driven pulley 34, the belt 33, and the driving pulley 36.

As described above, when one folded sheet S is held by each of the clamping devices, the first sheet discharge path 7J and the second sheet discharge path 7K are switched over every time the decelerating roller 5 rotates 90 degrees. In such a case, the rotating cam 32 rotates at twice the rotating speed of the decelerating roller 5. On the other hand, when two folded sheets S are held by each of the clamping devices, the first sheet discharge path 7J and the second sheet discharge path 7K are switched over every time the decelerating roller 5 rotates 180 degrees. In such a case, the rotating cam 32 rotates at the same rotating speed as that of the decelerating roller 5. The rotating speed of the rotating cam 32 can be changed by adjusting the rotating speed of the motor 35. Alternatively, a mechanism to vary a change gear ratio can be arranged between the motor 35 and the rotating cam 32, so that the rotating speed of the rotating cam 32 can be changed.

According to the embodiment, the first sheet releasing unit causes the first sheet holding unit and the second sheet holding unit to release the folded sheet into the first sheet discharge path. The second sheet releasing unit causes at least the second sheet holding unit to release the folded sheet into the second sheet discharge path. The sheet-delivery switching unit causes the first sheet releasing unit not to move the second sheet holding unit depending on the number of folded sheets in a pile, i.e., the number of folded sheets held by each of the sheet holding units. With the above-described configuration, when a plurality of folded sheets is delivered by each of the sheet holding units, the folded sheets can be discharged to the two sheet discharge paths. Therefore, it is possible to provide more allowance for a process performed after the folded sheet is delivered to the sheet discharge path. As a result, the devices to be used in a subsequent process can be operated with less load, and reduction of durability of the devices can be suppressed.

When a plurality of folded sheets is held by each of the sheet holding units, the folded sheets are discharged to the two sheet discharge paths by controlling the movement of the first and the second sheet holding units arranged on the sheet delivering unit (decelerating roller). Because the one decelerating roller is used to discharge the folded sheet to the two sheet discharge paths, it is possible to reduce points where the folded sheet needs to be delivered from the holding roller to the decelerating roller with high precision, and the adjustment between the decelerating roller and the holding roller can be reduced. Because the decelerating roller is expensive, the decrease in the number of decelerating rollers can reduce costs of the folding device.

The folded sheet may be delivered in an unsteady manner from the holding roller to the decelerating rollers. However, according to the embodiment, the folded sheet is delivered to the one decelerating roller from the holding roller, so that the folded sheet can be delivered to the sheet discharge paths in a steady manner. Furthermore, because the mechanism is configured to delivery the folded sheet to the sheet discharge paths, the accuracy of the discharging can be improved. As a result, the accuracy of operation, such as operation by the chopper folding device, performed in the sheet discharge path can be improved.

According to an aspect of the present invention, there is provided the folding device including a plurality of sheet carrying paths. When a plurality of folded sheets is delivered by each of the sheet holding units, the folded sheets can be discharged to a plurality of sheet discharge paths. Furthermore, it is possible to reduce contact points where the folded sheet is delivered from the holding roller to the decelerating roller with high precision.

Although the invention has been described with respect to specific embodiments for a complete and clear disclosure, the appended claims are not to be thus limited but are to be construed as embodying all modifications and alternative constructions that may occur to one skilled in the art that fairly fall within the basic teaching herein set forth. 

1. A folded-sheet carrying path switching mechanism that carries a pile of folded sheets, the folded sheets being in a predetermined shape and size, the folded-sheet carrying path switching mechanism comprising: a delivering unit that receives the pile and delivers the pile to one of a first path and a second path, the delivering unit including a rotatable member; a first holding unit that is mounted on the rotatable member, and configured to receive the pile in a first position while the rotatable member is rotating and deliver the pile to the first path; and a second holding unit that is mounted on the rotatable member, and configured to receive the pile in a second position while the rotatable member is rotating and deliver the pile to one of the first path and the second path; and a switching unit that includes a releasing unit that causes the first holding unit to release the pile into the first path and causes the second holding unit to release the pile into any one of the first path and the second path; and a control unit that controls the releasing unit to cause the second holding unit to release the pile in any one of the first path and the second path depending on number of folded sheets in the pile.
 2. The folded-sheet carrying path switching mechanism according to claim 1, wherein the releasing unit includes a first cam having a plurality of concave portions to cause the first holding unit to release the pile into the first path and cause the second holding unit to release the pile into any one of the first path and the second path, wherein the first cam is configured to rotate around a rotation axis of the rotatable member, and the control unit includes a second cam configured to cause the second holding unit not to release the pile into the first path depending on number of folded sheets in the pile, wherein the second cam is configured to rotate around a rotation axis of the rotatable member.
 3. The folded-sheet carrying path switching mechanism according to claim 1, wherein the control unit controls the releasing unit to cause the second holding unit to release the pile into the first path when the number of folded sheets in the pile is one, and controls the releasing unit to cause the second holding unit to release the pile into the second path when the number of folded sheets in the pile is more than one.
 4. The folded-sheet carrying path switching mechanism according to claim 1, further comprising a sheet delivery guide that switches between a first discharge mode and a second discharge mode depending on the number of folded sheets in the pile, wherein the first discharge mode causes the first holding unit and the second holding unit to discharge the pile into the first path, and the second discharge mode causes the first holding unit to discharge the pile into the first path, and causes the second holding unit to discharge the pile into the second path.
 5. The folded-sheet carrying path switching mechanism according to claim 4, further comprising: a first cam including a plurality of concave portions to move the sheet delivery guide to cause the first holding unit and the second holding unit to discharge the pile into the first path, wherein the first cam is configured to rotate around a rotation axis of the rotatable member; and a second rotating cam to move the sheet delivery guide to cause the second holding unit not to discharge the pile into the first path but to discharge the pile into the second path, wherein the second cam is configured to rotate around a rotation axis of the rotatable member.
 6. The folded-sheet carrying path switching mechanism according to claim 4, further comprising a rotating cam including a first concave portion that moves the sheet delivery guide to discharge the pile into the first path; and a second concave portion that moves the sheet delivery guide to discharge the pile into the second path; and a speed controlling unit that changes rotating speed of the rotating cam depending on the number of folded sheets in the pile.
 7. The folded-sheet carrying path switching mechanism according to claim 4, further comprising a mode setting unit that sets the first discharge mode when the number of folded sheets in the pile is one, and sets the second discharge mode when the number of folded sheets in the pile is more than one.
 8. The folded-sheet carrying path switching mechanism according to claim 1, wherein the folded sheet is produced by printing a predetermined image on the folded sheet and being cut out to a predetermined size.
 9. A folding device comprising: a folding roller that is configured to fold a sheet in a predetermined shape and size, and produce a pile of folded sheets; and a folded-sheet carrying path switching mechanism including a delivering unit that receives the pile and delivers the pile to one of a first path and a second path, the delivering unit including a rotatable member; a first holding unit that is mounted on the rotatable member, and configured to receive the pile in a first position while the rotatable member is rotating and deliver the pile to the first path; and a second holding unit that is mounted on the rotatable member, and configured to receive the pile in a second position while the rotatable member is rotating and deliver the pile to one of the first path and the second path; and a switching unit that includes a releasing unit that causes the first holding unit to release the pile into the first path and causes the second holding unit to release the pile into any one of the first path and the second path; and a control unit that controls the releasing unit to cause the second holding unit to release the pile in any one of the first path and the second path depending on number of folded sheets in the pile.
 10. The folding device according to claim 9, wherein the folded sheet is produced by printing a predetermined image on the folded sheet and being cut out to a predetermined size. 